JP6167835B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus such as a flatbed scanner.

  2. Description of the Related Art Conventionally, as an example of an image reading apparatus, a flat having a reading carriage mounted with a sensor for reading a document and scanning in a scanning direction, an annular belt that pulls the reading carriage, and three pulleys around which the belt is wound. There is a bed type scanner.

  In such an image reading apparatus, two of the three pulleys are arranged at both ends of the scanning area of the reading carriage, while the remaining one pulley is arranged at a position overlapping the scanning area of the reading carriage, so that the belt is triangular. There is a case of stretching (for example, Patent Document 1).

JP 2004-133151 A

  By the way, in the image reading apparatus, in order to detect the presence / absence of a document placed on the document table, a detection unit such as a reflective optical sensor is provided on the opposite side of the document surface on which the document is placed on the document table. May be placed. Since such a detection unit is located at a position overlapping the scanning area of the reading carriage, there is a possibility that the detection unit may interfere with a belt stretched in a triangular shape.

  SUMMARY An advantage of some aspects of the invention is that it provides an image reading apparatus that can suppress interference between a belt that pulls a reading carriage and a detection unit that detects a document. is there.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
An image reading apparatus that solves the above-described problems is a document table having a document placement surface on a first surface, and placed on the placement surface from a second surface side opposite to the first surface of the document table. A detection unit for detecting the original document, a reading unit for reading the document placed on the mounting surface from the second surface side of the document table, and scanning along the document table by mounting the reading unit. A reading carriage that scans in the direction, and an annular belt that pulls the reading carriage, the belt extending in the scanning direction and having the reading carriage fixed thereto, and the first side And the second side portion disposed with a gap between the first detection portion and the second detection portion, and the detection portion is disposed in a region between the first side portion and the second side portion of the belt.

  According to this configuration, since the detection unit is arranged in the region between the first side and the second side of the belt, interference between the belt that pulls the reading carriage and the detection unit that detects the document is suppressed. can do. In addition, since the reading carriage is fixed to the first side extending in the belt scanning direction, the inclination of the reading carriage pulled by the belt during scanning can be suppressed.

  In the image reading apparatus, a first pulley and a second pulley arranged in the scanning direction, and a third pulley arranged at a position different from the first pulley and the second pulley in a direction intersecting the scanning direction. The belt is wound around the first pulley, the second pulley, and the third pulley, and the first side portion is formed between the first pulley and the second pulley.

  According to this configuration, since the belt is wound around the three pulleys, the area between the first side and the second side can be made wider than when the belt is wound around the two pulleys. Thereby, the freedom degree of arrangement | positioning of the detection part arrange | positioned in the area | region between a 1st edge part and a 2nd edge part can be made high.

  The image reading apparatus includes a driving source for scanning the reading carriage, the third pulley is a driving pulley that is rotated by a driving force of the driving source, and the driving source includes the first pulley and the first pulley. It is arranged at a position closer to the third pulley than the two pulleys.

  According to this configuration, the path for transmitting the driving force of the driving source to the driving pulley can be shortened by arranging the driving source closer to the third pulley than the first pulley and the second pulley.

  In the image reading apparatus, the placement surface has an origin set at a first end in a direction intersecting with the scanning direction, and the third pulley is configured such that the first pulley and the first pulley in the direction intersecting with the scanning direction The second pulley is disposed at a position closer to the origin than the second pulley, and is closer to the second pulley than the first pulley in the scanning direction, and the second side portion includes the first pulley and the first pulley. It is formed between the third pulley.

  According to this configuration, the third pulley is arranged between the first side and the second side of the belt by disposing the third pulley closer to the origin side than the first pulley and the second pulley in the direction intersecting the scanning direction. The area to be formed can be widened toward the origin side in the scanning direction. Therefore, the detection part arrange | positioned in the area | region between a 1st edge part and a 2nd edge part can be arrange | positioned in the position nearer to an origin.

  In the image reading apparatus, when the origin is set on the first end in the direction intersecting the scanning direction on the placement surface, and the detection unit that detects the first-size document is the first detection unit. A second detection unit that detects a document having a size larger than the first size, and the second detection unit is disposed at a position farther from the origin than the belt in a direction intersecting the scanning direction. .

  According to this configuration, in addition to disposing the first detection unit between the first side and the second side of the belt in a direction intersecting the scanning direction, the position is further away from the origin than the belt. By arranging the second detection unit, it is possible to detect documents of a plurality of sizes.

  The image reading apparatus includes a guide rail that guides scanning of the reading carriage, and when the direction intersecting the scanning direction is a longitudinal direction of the reading carriage, the reading carriage is separated from both ends in the longitudinal direction. It has an engaging portion for the guide rail at a position, and is fixed to the belt at a position closer to the engaging portion than the both ends.

  According to the above configuration, since the reading carriage has the engaging portion with respect to the guide rail at a position away from both ends in the longitudinal direction, the inclination of the reading carriage in the vertical direction can be increased by arranging the guide rail near the center of gravity of the reading carriage. Can be suppressed. In addition, since the reading carriage is fixed at a position close to the engaging portion that engages with the guide rail, the inclination of the reading carriage pulled by the belt with respect to the scanning direction can be suppressed.

1 is a perspective view of a multi-function peripheral including an image reading apparatus according to an embodiment. FIG. 2 is a top view of a multifunction machine in which an opening / closing body is disposed in an open position. The top view of an image reading apparatus. FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. The table | surface which shows the relationship between the output result of a detection part, and the original document detected.

Hereinafter, embodiments of an image reading apparatus will be described with reference to the drawings.
The image reading device is, for example, a flat bed type scanner that constitutes a multi-function peripheral by being stacked in the vertical direction of a printer that is an example of a recording device.

  As illustrated in FIG. 1, a multifunction machine 11 according to the present embodiment includes a recording device 21 that performs printing (recording) on a recording medium S such as paper, and an image reading device that is disposed so as to overlap the recording device 21 in the vertical direction. 31.

  In the multifunction device 11, an operation panel 13 for operating the multifunction device 11 protrudes forward from the front side of the apparatus main body 12 in which the recording device 21 and the image reading device 31 are integrated. For example, a display unit or operation buttons for displaying a menu screen or the like can be arranged on the operation panel 13.

  A cover member 14 that covers an opening (not shown) for inserting the recording medium S is provided on the back side of the apparatus main body 12. A discharge unit 15 for discharging the recording medium S is provided on the front side of the apparatus main body 12 at a position below the operation panel 13 in the vertical direction. A storage cassette 17 that stores a plurality of recording media S in a stacked state is detachably attached to the lower portion of the apparatus main body 12.

  As shown in FIG. 2, the image reading device 31 includes a bottomed box-shaped reading unit case 32, a document table 33 and a reading table 34 fitted in the upper opening of the reading unit case 32, and a document table 33 and a reading unit. A frame member 35 for fixing the base 34 and an opening / closing body 37 rotatably attached via a hinge 36 provided on the back side are provided.

  The document table 33 and the reading table 34 can be made of, for example, a square plate-shaped transparent glass. The reading table 34 is shorter than the document table 33 in the longitudinal direction (left and right direction in FIG. 2) of the apparatus main body 12. The reading table 34 is arranged on one side (left side in FIG. 2) of the document table 33 in the longitudinal direction of the apparatus main body 12.

  The opening / closing body 37 is, for example, an auto document feeder that feeds a plurality of stacked originals G onto the reading table 34 while inverting one by one. A document pressing white plate 38 for pressing the document G placed on the document table 33 is attached to the opening / closing body 37. The opening / closing body 37 may be a plate-shaped lid member provided with a document pressing white plate 38. When the opening / closing body 37 is a lid member that does not function as an auto document feeder, the reading table 34 may not be provided.

  The document table 33 has a rectangular placement surface 61 on which the document G is placed on the first surface which is the upper surface in the present embodiment. The mounting surface 61 is one end in the longitudinal direction of the apparatus main body 12 (left end in FIG. 2), and in the depth direction intersecting with the longitudinal direction, the first end on the back side near the rotation axis AX of the opening / closing body 37. Has an origin OP.

  The first outer edge 62 of the mounting surface 61 extends from the origin OP in the longitudinal direction of the apparatus main body 12 (right direction in FIG. 2), while the second outer edge 63 of the mounting surface 61 extends from the origin OP in the scanning direction. It extends in a direction intersecting with X (in this embodiment, a front direction opposite to the depth direction of the apparatus main body 12). The placement surface 61 has a third outer edge 64 at a position facing the first outer edge 62, and a fourth outer edge 65 at a position facing the second outer edge 63.

  The document pressing white plate 38 is configured to be displaceable between a closed position that overlaps the placement surface 61 and an open position that is away from the placement surface 61 when the opening / closing body 37 rotates about the rotation axis AX. Yes. In FIG. 2, in order to clearly show the document pressing white plate 38, a state in which the opening / closing body 37 is widened so that the document pressing white plate 38 forms an obtuse angle with the placement surface 61 is illustrated. Need only be open to the extent that the document G can be placed on the placement surface 61.

  The image reading apparatus 31 includes a first opening / closing lever 66 disposed behind the document table 33 in the depth direction and a first opening / closing lever 66 disposed farther from the rotation axis AX than the first opening / closing lever 66 in the depth direction. A two opening / closing lever 67 is provided so as to protrude from the frame member 35.

  A guide rail 41 that extends in the longitudinal direction of the apparatus main body 12 (left-right direction in FIG. 2) protrudes from the bottom of the reading unit case 32. A reading carriage 42 is accommodated in the reading unit case 32 along the document table 33. The reading carriage 42 has an engaging portion 43 that engages with the guide rail 41, and is supported by the guide rail 41 via the engaging portion 43. The reading carriage 42 is equipped with a reading unit 44 that reads the document G placed on the document table 33 from the second surface side (the lower surface side in the present embodiment) opposite to the first surface of the document table 33. . The reading unit 44 is, for example, a contact type image sensor.

  The reading carriage 42 is reciprocated and scanned along the scanning direction X that is the longitudinal direction of the apparatus main body 12 by being guided by the guide rail 41. Note that the engaging portion 43 of the reading carriage 42 with respect to the guide rail 41 is preferably arranged near the center of gravity of the reading carriage 42, so the engaging portion 43 is arranged near the center in the longitudinal direction Y of the reading carriage 42. . In the following description, the longitudinal direction Y of the reading carriage 42 may be simply referred to as the longitudinal direction Y. That is, the reading carriage 42 has an engaging portion 43 for the guide rail 41 at a position away from both ends in the longitudinal direction Y. In the present embodiment, the longitudinal direction Y of the reading carriage 42 is a direction that intersects the scanning direction X.

  On the bottom of the reading unit case 32, a plurality of detection units 71 that detect a document placed on the placement surface 61 from the second surface side of the document table 33 are arranged. The detection unit 71 receives, for example, a light projecting unit that emits light from the second surface side of the document table 33 toward the placement surface 61 and reflected light from the document G placed on the placement surface 61. It is a reflection type optical sensor having a light receiving part.

  A plurality of (two in the present embodiment) detectors 71X (71X1, 71X2) arranged in the scanning direction X detect the length of the document G in the scanning direction X. A plurality (five in the present embodiment) of detection units 71Y (71Y1, 71Y2, 71Y3, 71Y4, 71Y5) arranged in the longitudinal direction Y detect the length of the document G in the longitudinal direction Y.

  In the present embodiment, among the plurality of detection units 71Y arranged in the longitudinal direction Y, the detection unit 71Y1 that is closest to the origin OP is positioned farther from the origin OP than the first detection unit 71 and the detection unit 71Y1. The arranged detectors 71Y2, 71Y3, 71Y4, 71Y5 may be referred to as second detectors. The first detection unit 71 detects, for example, a first size (for example, A5 size) original G, and the second detection unit has a size larger than the first size (for example, B5, A4, B4, A3). , Etc.) is detected.

  As shown in FIG. 3, the reading unit case 32 accommodates a drive source 45 for scanning the reading carriage 42 and a transmission mechanism 46 for transmitting the driving force of the driving source 45 to the reading carriage 42. In FIG. 3, the reading table 34 and the frame member 35 are not shown and the document table 33 is indicated by a dotted line in order to clearly show the configuration inside the reading unit case 32.

  The drive source 45 is, for example, a motor that can be driven to rotate in a second direction that is opposite to the first direction and the first direction. For example, when the motor is rotationally driven in the first direction, the reading carriage 42 scans in the forward direction in the scanning direction X (rightward in FIG. 3), while when the motor is rotationally driven in the second direction, the reading carriage 42 is scanned in the scanning direction. The backward scanning is performed in the opposite direction to X (leftward in FIG. 3).

  As shown in FIG. 4, the bottom of the reading unit case 32 is directed downward so that a driving source housing 40 having a recess for housing the driving source 45 on the upper surface protrudes toward the recording device 21. Projected. The drive source 45 is accommodated in the drive source accommodating portion 40 and is disposed below the reading carriage 42 so as not to interfere with the reading carriage 42.

  As shown in FIG. 3, the bottom of the reading unit case 32 is a reinforcing member extending in the scanning direction X at a position aligned with the guide rail 41 in the longitudinal direction Y (in the present embodiment, on the back side of the guide rail 41). A sheet metal member 47 is fixed. The drive source 45 and the drive source accommodating portion 40 are located behind the guide rail 41 and the sheet metal member 47 in the depth direction along the longitudinal direction Y, and the first end side in the scanning direction X of the apparatus main body 12 (see FIG. 3 on the left end side).

  The transmission mechanism 46 includes a first pulley 52 and a second pulley 53 that are arranged in the scanning direction X along the guide rail 41, a third pulley 51, and an annular belt 54 that pulls the reading carriage 42. The third pulley 51 is located at a position different from the first pulley 52 and the second pulley 53 in the longitudinal direction Y intersecting the scanning direction X, specifically, the first pulley 51 and the pulleys 52 and 53 in the longitudinal direction Y. Are arranged at a position on the outer edge 62 side (position on the origin OP side).

  The third pulley 51 is a driving pulley that is rotated by the driving force of the driving source 45. The first pulley 52 and the second pulley 53 are driven pulleys that are rotatably disposed at both ends of the sheet metal member 47. In the scanning direction X, the third pulley 51 is disposed at a position closer to the second pulley 53 than the first pulley 52. Further, since it is preferable that the path for transmitting the driving force of the driving source 45 to the driving pulley is short, the driving source 45 is disposed at a position closer to the third pulley 51 than the first pulley 52 and the second pulley 53. .

  The belt 54 is wound around the pulleys 51, 52, 53, and is formed between the first side portion 54 a formed between the first pulley 52 and the second pulley 53, and between the third pulley 51 and the first pulley 52. The second side portion 54b is formed in a triangular shape having a third side portion 54c formed between the third pulley 51 and the second pulley 53.

  The second side portion 54b of the belt 54 is disposed with a gap between the second side portion 54b and the first side portion 54a in the longitudinal direction Y. The first detection unit 71 is disposed in a region between the first side 54 a and the second side 54 b of the belt 54 in the longitudinal direction Y intersecting the scanning direction X. Further, the second detection units 71Y2, 71Y3, 71Y4, 71Y5 are arranged at positions farther from the origin OP than the belt 54 in the longitudinal direction Y.

  The reading carriage 42 is fixed to a first side 54 a of a belt 54 that is stretched in the scanning direction X so as to be parallel to the guide rail 41 between the two pulleys 52 and 53. When the drive source 45 is driven, the third pulley 51 rotates to move the belt 54 around. Then, the pulleys 52 and 53 rotate following the rotating belt 54 and simultaneously the reading carriage 42 fixed to the belt 54 scans along the scanning direction X.

  Therefore, a region between the first pulley 52 and the second pulley 53 in the scanning direction X becomes a scanning region of the reading carriage 42. The detection unit 71 is disposed at a position overlapping the scanning region of the reading carriage 42 in plan view.

  Since the reading carriage 42 has the engaging portions 43 at positions away from both ends in the longitudinal direction Y, the reading carriage 42 is preferably fixed to the belt 54 at a position closer to the engaging portions 43 than both ends in the longitudinal direction Y. As described above, by fixing the reading carriage 42 to the belt 54 near the guide rail 41, the horizontal tilt of the reading carriage 42 pulled by the belt 54 is suppressed.

  Further, the outer peripheral surface around which the belt 54 of the third pulley 51 is wound is preferably located at a position farther from the first pulley 52 than the outer peripheral surface of the second pulley 53 disposed near the third pulley 51. . Accordingly, the belt 54 is stretched in a triangular shape in which the first side portion 54a and the third side portion 54c form an obtuse angle and the second side portion 54b and the third side portion 54c form an acute angle. As a result, the winding distance of the belt 54 with respect to the third pulley 51 becomes longer than when the third pulley 51 is arranged between the two pulleys 52 and 53 in the scanning direction X (that is, the winding angle of the belt 54). Therefore, the slippage of the belt 54 with respect to the third pulley 51 that is the driving pulley is suppressed.

  However, if the distance between the third pulley 51 and the second pulley 53 in the scanning direction X is increased, the winding distance of the belt 54 around the second pulley 53 is shortened or the apparatus body 12 is increased in size. It is not preferable. Therefore, the third pulley 51 is aligned with the second pulley 53 in the longitudinal direction Y, and the diameter of the outer peripheral surface around which the belt 54 is wound is made larger than that of the second pulley 53, so that the portion around which the belt 54 is wound is formed. The outer peripheral surface is slightly disposed outside the first pulley 52 in the scanning direction X. As a result of arranging the three pulleys 51, 52, 53 in this way, the third side portion 54c is the shortest side among the three sides formed by the belt 54.

  The third pulley 51 has a larger diameter on the outer peripheral surface around which the belt 54 is wound than the pulleys 52 and 53. The third pulley 51 has a longer winding distance of the belt 54 with respect to the third pulley 51, so This contributes to suppressing the slip of the belt 54. Further, the belt 54 is a toothed belt having a tooth portion on the inner diameter side, and a tooth portion is provided on the outer peripheral surface of the pulleys 51, 52, 53 to suppress slippage of the belt 54 with respect to the pulleys 51, 52, 53. It may be.

Next, the operation of the image reading apparatus 31 configured as described above will be described.
When reading the document G, first, the opening / closing body 37 is placed in the open position so that the surface of the document G to be read faces the placement surface 61 and the corner of the document G is positioned at the origin OP. The original G is placed on the original table 33 while being aligned with the original position.

  When the placement of the original G is completed, the opening / closing body 37 in the open position is rotated toward the closed position. Then, when the opening / closing body 37 rotates to a position where the first opening / closing lever 66 is pressed, the detection unit 71 detects the document G placed on the placement surface 61.

  When the detection unit 71 is a reflection type optical sensor, the detection result of the original G is output from the light projecting unit and the detection result based on the amount of light received by the light receiving unit. For example, when the light quantity received by the light receiving unit is greater than or equal to a threshold when the light projecting unit emits light toward the placement surface 61, the emitted light is reflected on the document G on the placement surface 61. As a result, a detection result “1” indicating that there is a document G is output. On the other hand, if the amount of light received by the light receiving unit is less than the threshold, a detection result “0” indicating that there is no document G is output.

  And as shown in FIG. 5, it is mounted on the mounting surface 61 based on the combination of the detection results (“1” or “0”) of the detection units 71Y1, 71Y2, 71Y3, 71Y4, 71Y5, 71X1, 71X2. The size and orientation of the original G are detected. When all the detection units 71 output “0”, a detection result that there is no document G is obtained.

  In addition, when the scanning direction X is a horizontal direction and the longitudinal direction Y is a longitudinal direction, when the document G is placed so that the scanning direction X is the longitudinal direction, the document is placed horizontally, and the longitudinal direction Y is the longitudinal direction. When the original G is placed, it is called “vertical placement”. 3 and 5, the original G (A5S) is horizontally placed in A5 size, the original G (A4L) is vertically placed in A4 size, the original G (B5S) is horizontally placed in B5 size, and the original G (A4S). Means A4 size landscape, document G (B4S) means B4 size landscape, and document G (A3S) means A3 size landscape.

  That is, the detection units 71X1, 71X2, 71Y1, 71Y2, 71Y3, 71Y4, 71Y5 overlap the corresponding original G in plan view so that the original G of a plurality of sizes and the orientation of the original G can be determined. Placed in position.

  Subsequently, when the opening / closing body 37 is further rotated and the second opening / closing lever 67 is pushed, it is detected that the original pressing white plate 38 is disposed at the closed position. When the opening / closing body 37 is placed at the closed position, the reading carriage 42 scans, and the reading unit 44 mounted on the reading carriage 42 reads the original G based on the detected size and orientation of the original G. Do.

  By the way, the detection units 71Y1, 71Y2, 71Y3, 71Y4, 71Y5 need to be arranged at positions where the document G of a plurality of sizes and the orientation of the document G can be determined. It ’s difficult to make big changes.

  In addition, since the engaging portion 43 of the reading carriage 42 is preferably arranged near the center of gravity of the reading carriage 42, the guide rail 41 and the engaging portion 43 are arranged near the center in the longitudinal direction Y of the reading carriage 42. become.

  Further, since the reading carriage 42 is preferably fixed to the belt 54 at a position close to the engaging portion 43, the belt 54 is arranged on the back side or the near side of the guide rail 41 in the longitudinal direction Y. In either case, the belt 54 needs to be disposed at a position where it does not interfere with the detection unit 71.

  Here, as shown in FIG. 4, the detection unit 71, the belt 54, and the guide rail 41 are all disposed below the reading carriage 42 in the vertical direction. In order to suppress the height (length in the vertical direction Z) of the multi-function device 11, the detection unit 71, the belt 54, and the guide rail 41 are arranged so as to overlap in the vertical direction Z and to be aligned in the horizontal direction. preferable.

  Therefore, in the present embodiment, the number of the detection units 71 arranged on the back side (the origin OP side) of the guide rail 41 is one, whereas the detection units 71 arranged on the labor side of the guide rail 41 are. Therefore, the belt 54 is disposed on the back side of the guide rail 41 where the number of the detectors 71 is small. And in the back side of the guide rail 41, the belt 54 is arranged in the region between the first side part 54a and the second side part 54b of the belt 54 so that the belt 54 has the first detection part 71. To avoid interference.

  In the present embodiment, since the belt 54 is wound around the three pulleys 51, 52, and 53, the first side portion 54a and the second side are compared with the case where the belt 54 is wound around the two pulleys 52 and 53. The area between the portion 54b is wide. Therefore, on the back side of the guide rail 41, the degree of freedom of arrangement of the first detection unit 71 arranged in the region between the first side part 54a and the second side part 54b of the belt 54 is increased.

  Further, as a result of arranging the belt 54 on the back side of the guide rail 41 in the depth direction that is the longitudinal direction Y, the three pulleys 51, 52, 53 and the drive source 45 are also arranged on the back side of the guide rail 41. .

  Here, since the drive source 45 is accommodated in the drive source accommodating portion 40 formed at the bottom of the reading unit case 32, it is disposed at a position overlapping the guide rail 41 formed at the bottom of the reading unit case 32. Is difficult. Since the drive source 45 is preferably arranged at a position close to the drive pulley, the two pulleys 52 and 53 arranged along the guide rail 41 are used as driven pulleys, while the second pulley 52 and 53 arranged at a position away from the guide rail 41 is used. The three pulleys 51 are preferably drive pulleys.

According to the above embodiment, the following effects can be obtained.
(1) Since the first detection unit 71 is disposed in an area between the first side 54 a and the second side 54 b of the belt 54, the belt 54 pulling the reading carriage 42 and the first document G are detected. Interference with the first detection unit 71 can be suppressed.

  (2) Since the reading carriage 42 is fixed to the first side portion 54 a extending in the scanning direction X of the belt 54, the inclination of the reading carriage 42 pulled by the belt 54 during scanning can be suppressed.

  (3) Since the belt 54 is wound around the three pulleys 51, 52, 53, the belt 54 is disposed between the first side portion 54 a and the second side portion 54 b as compared with the case where the belt 54 is wound around the two pulleys 52, 53. The area can be widened. Thereby, the freedom degree of arrangement | positioning of the 1st detection part 71 arrange | positioned in the area | region between the 1st edge part 54a and the 2nd edge part 54b can be made high.

  (4) By disposing the drive source 45 at a position closer to the third pulley 51 than to the first pulley 52 and the second pulley 53, the path for transmitting the drive force of the drive source 45 to the drive pulley can be shortened. .

  (5) By disposing the third pulley 51 closer to the origin OP side than the first pulley 52 and the second pulley 53 in the direction intersecting the scanning direction X (longitudinal direction Y), the first side portion 54a of the belt 54 A region formed between the second side portion 54b can be widened toward the origin OP side in the scanning direction X. Therefore, the detection part 71 arrange | positioned in the area | region between the 1st edge part 54a and the 2nd edge part 54b can be arrange | positioned in the position closer to origin OP.

  (6) In the longitudinal direction Y intersecting with the scanning direction X, in addition to disposing the first detection unit 71 between the first side part 54a and the second side part 54b of the belt 54, the origin is more than the belt 54. By disposing the second detectors 71Y2, 71Y3, 71Y4, 71Y5 at positions away from the OP, it is possible to detect the document G having a plurality of sizes.

  (7) Since the reading carriage 42 has the engaging portion 43 with respect to the guide rail 41 at a position away from both ends in the longitudinal direction Y, the guide carriage 41 is arranged in the vicinity of the center of gravity of the reading carriage 42 so that the vertical position of the reading carriage 42 is increased. The inclination in the direction Z can be suppressed. Further, since the reading carriage 42 has the belt 54 fixed at a position close to the engaging portion 43 that engages with the guide rail 41, the inclination of the reading carriage 42 pulled by the belt 54 with respect to the scanning direction X can be suppressed. .

In addition, you may change the said embodiment as follows.
-The belt 54 may be wound around two pulleys. For example, the pulley 51 may not be provided, and the belt 54 may be wound around the two pulleys 52 and 53. In this case, for example, if the driving force of the driving source 45 is transmitted to the second pulley 53 via a transmission mechanism such as a gear train, the driving source accommodating portion 40 is disposed at a position away from the guide rail 41. be able to. Furthermore, if the second pulley 53 is made larger in diameter than the first pulley 52, a substantially triangular gap (region) in plan view is formed between the first side portion 54a and the second side portion 54b. The degree of freedom in arrangement when arranging the first detection unit 71 can be increased.

  The belt 54 may be wound around four or more pulleys. For example, the fourth pulley is disposed at a position closer to the first outer edge 62 in the longitudinal direction Y than the first pulley 52 and closer to the fourth outer edge 65 in the scanning direction X than the third pulley 51. The belt 54 may be wound around these first to fourth pulleys. According to this configuration, the belt 54 is stretched in a square shape in plan view, the first side 54 a is formed between the first pulley 52 and the second pulley 53, and the second side 54 b is the first side. It is formed between the 3 pulley 51 and the 4th pulley. Therefore, the region formed between the first side portion 54a and the second side portion 54b can be made wider, and the degree of freedom in arrangement when arranging the detection unit 71 can be increased.

  The reading carriage 42 may be supported by a plurality of guide rails 41 arranged in the longitudinal direction Y. According to this configuration, the inclination of the reading carriage 42 in the horizontal direction and the vertical direction Z can be suppressed. And when employ | adopting this structure, you may arrange | position the belt 54 and the detection part 71 between the two guide rails 41 located in a line with the longitudinal direction Y, or the guide rail 41 located in the edge part in the longitudinal direction Y. Further, the belt 54 and the detection unit 71 may be disposed on the back side or the near side.

  In the mounting surface 61, the outer edges 63 and 65 extending in the longitudinal direction Y may be longer than the outer edges 62 and 64 extending in the scanning direction X, and the lengths of the outer edges 62 and 64 and the outer edges 63 and 65 are equal. Also good. Moreover, the shape of the mounting surface 61 may not be rectangular.

  The number and arrangement of the detection units 71 can be arbitrarily changed according to the size and orientation of the document G to be detected. For example, only one detection unit 71 may be provided to detect only the presence or absence of the document G, or a plurality of detection units 71 may be arranged in an area formed inside the ring of the belt 54. .

  The recording device 21 provided in the multifunction machine 11 is not limited to a printer, and may be, for example, a facsimile or a copying machine. Further, the image reading device 31 is not limited to a scanner, and may be, for example, a card reader or an authentication device.

Furthermore, the technical idea grasped | ascertained from the said embodiment and each modification is described below.
(A) a document table having a document placement surface on the first surface;
A detection unit for detecting a document placed on the placement surface from a second surface side opposite to the first surface of the document table;
A reading unit that reads a document placed on the placement surface from the second surface side of the document table;
A reading carriage that mounts the reading unit and scans in the scanning direction along the document table;
An annular belt for pulling the reading carriage;
With
The image reading apparatus according to claim 1, wherein the detection unit is arranged in a region formed inside the belt ring.

  According to this configuration, since the detection unit is disposed in the region formed inside the belt ring, the interference between the belt that pulls the reading carriage and the detection unit that is disposed at a position overlapping the scanning region of the reading carriage. Can be suppressed.

  G: Document, X: Scanning direction, Y: Longitudinal direction, OP ... Origin, 31 ... Image reading device, 33 ... Document table, 41 ... Guide rail, 42 ... Reading carriage, 43 ... Engagement unit, 44 ... Reading unit, 45 ... Drive source, 51 ... Third pulley, 52 ... First pulley, 53 ... Second pulley, 54 ... Belt, 54a ... First side, 54b ... Second side, 61 ... Placing surface, 71, 71X , 71Y, 71X1, 71X2, 71Y1, 71Y2, 71Y3, 71Y4, 71Y5 ... detection unit, 71Y1 ... first detection unit, 71Y2, 71Y3, 71Y4, 71Y5 ... second detection unit.

Claims (7)

A document table having a document placement surface on a first surface;
A detection unit for detecting a document placed on the placement surface from a second surface side opposite to the first surface of the document table;
A reading unit that reads a document placed on the placement surface from the second surface side of the document table;
A reading carriage that mounts the reading unit and scans in the scanning direction along the document table;
An annular belt for pulling the reading carriage;
With
The belt includes a first side that extends in the scanning direction and to which the reading carriage is fixed, and a second side that is disposed with a gap between the first side and the belt.
The image reading apparatus according to claim 1, wherein the detection unit is disposed in a region between the first side and the second side of the belt. A first pulley and a second pulley arranged in the scanning direction;
A third pulley disposed in a position different from the first pulley and the second pulley in a direction intersecting the scanning direction;
The belt is wound around the first pulley, the second pulley, and the third pulley, and the first side portion is formed between the first pulley and the second pulley. The image reading apparatus according to claim 1. A drive source for scanning the reading carriage;
The third pulley is a driving pulley that is rotated by a driving force of the driving source,
The image reading apparatus according to claim 2, wherein the driving source is disposed at a position closer to the third pulley than the first pulley and the second pulley. In the mounting surface, an origin is set at a first end in a direction intersecting the scanning direction,
The third pulley is located closer to the origin side than the first pulley and the second pulley in a direction intersecting the scanning direction, and the second pulley is more than the first pulley in the scanning direction. Placed near the pulley,
The image reading apparatus according to claim 2, wherein the second side portion is formed between the first pulley and the third pulley. In the mounting surface, an origin is set at a first end in a direction intersecting the scanning direction,
A second detection unit for detecting a document of a size larger than the first size when the detection unit for detecting a document of a first size is the first detection unit;
The said 2nd detection part is arrange | positioned in the position away from the said origin rather than the said belt in the direction which cross | intersects the said scanning direction, The Claim 1 characterized by the above-mentioned. Image reading device. A guide rail for guiding scanning of the reading carriage;
When the direction intersecting the scanning direction is the longitudinal direction of the reading carriage, the reading carriage has an engaging portion for the guide rail at a position away from both ends in the longitudinal direction, and the engagement is more than the both ends. The image reading apparatus according to claim 1, wherein the image reading apparatus is fixed to the belt at a position close to the joint.   The image reading apparatus according to claim 6, wherein the guide rail is disposed at a central position in the longitudinal direction of the reading carriage.